How do you align your chain?

[joeswamp]

The chain on my track bike was running a little noisy in September, so I did the traditional alignment thing with string (where you pull a string tight along the edges of the rear tire and adjust until the front tire is centered). That quieted the chain a lot, but it also started me thinking...

The string method aligns the rear wheel to the front, but it seems that what you're really trying to do here is align the rear wheel sprocket to the engine sprocket. The string method assumes the frame is perfectly straight and the engine is mounted perfectly in the frame. I've seen these expensive big caliper tools that precisely align the rear axle to the swingarm pivot, this seems better but it still assumes the engine is perfectly mounted.

I've seen tools that clamp to the rear sprocket and extend a rod (or laser beam) along the chain that you're supposed to line up by eye. This appears to be the most direct measurement but it's also a little sloppy -- seems what you'd want is an adjustable length straightedge that somehow lies flat against both sprocket surfaces...

Has anybody used any of these tools? What do you folks think is the best method?

[Currently]

Joe ... put that engineering degree to work and come up with a patent ...

Sounds like you got yourself a great alignment idea!

I use aluminum angle iron clamped to the rear wheel and I measure the front tire offset so that it is even on both sides.

[Currently]

i used to measure from a common point on both sides of the frame to the ends of the rear axle. now I just eye it(sprocket to sprocket) & then check w/ the measurement. usually right on. i think the laser alignment is overkill.

Which side of your mouth do you stick your tongue out when eyeballing it?

[TTD]

I have a version of this tool...

RhinoMoto motorcycle parts installation tools


It basically aligns the rear axle with the swingarm pivot.


This doesn't mean the front wheel is aligned with the back though... but it's better than nothing.

[Degsy]

The string method aligns the rear wheel to the front, but it seems that what you're really trying to do here is align the rear wheel sprocket to the engine sprocket.

depends if you want perfect handling or perfect chain/sprocket wear. Wheel to wheel would be better for handling, sprocket to sprocket for less chain wear (assuming a tweaked frame).

I use the alignment marks on the chain adjuster blocks, then spin the rear wheel and make sure by eyeball (tongue on left) that the chain looks like it is meeting the rear sprocket squarely and I have never had a problem.

degs

[Currently]

Thank YOU Degs for the ultimate insight in alignment ... that is where I was going wrong ... will see if the left works better!

[Mad Max]

depends if you want perfect handling or perfect chain/sprocket wear. Wheel to wheel would be better for handling, sprocket to sprocket for less chain wear (assuming a tweaked frame).

I use the alignment marks on the chain adjuster blocks, then spin the rear wheel and make sure by eyeball (tongue on left) that the chain looks like it is meeting the rear sprocket squarely and I have never had a problem.

degs

+1

[Kurlon]

I roll the wheel forward and watch how the chain lies on the rear sprocket, when I'm aligned with the front, it puts the teeth evenly between the links looking at from the back of the bike towards the front. (Mid point of chain contact on the rear sprocket)

[joeswamp]

depends if you want perfect handling or perfect chain/sprocket wear. Wheel to wheel would be better for handling, sprocket to sprocket for less chain wear (assuming a tweaked frame).

That's a good point, I'd forgotten about the handling implications. I'm guessing that if your rear wheel were significantly offset from your front wheel you'd have radically different turn in behaviors and/or stability going left or going right. Makes me wonder if guys that only turn one way (like flat track racers) would have a reason to deliberately offset the wheels from one another.

In my case I found the front wheel to be about 3/8" offcenter when I did the string thing. After centering it I noticed no change in handling but I did notice a lot less chain noise, which suggests the sprockets are more sensitive to misalignment. On the other hand I'm pretty darned slow so maybe that would change if someone else were riding the bike...

I use the alignment marks on the chain adjuster blocks, then spin the rear wheel and make sure by eyeball (tongue on left) that the chain looks like it is meeting the rear sprocket squarely and I have never had a problem.

I've worked on more than a few bikes where those hash marks are quite inaccurate. On my SV they're off by about 1/3 of a mark. It's odd to me that they can set up the engine/frame/swingarm/forks so that the chain precisely aligns when the tires centerlines do, yet they can't figure out how to put these marks in the right place.

I think I once saw MotoGP mechanics using the swingarm/axle caliper thing that Tony uses. I guess going off the frame must be a reasonable compromise between the chain and wheel alignment. That, and it's probably also the fastest method that's accurate enough.

[akira700]

I have a version of this tool...

RhinoMoto motorcycle parts installation tools

Man Tony that thing is $150 !
I just spin it and eyeball it. Never had noise. Joe, you sure that your
chain or sprocket aint just shot?

[ZX-12R]

The first couple times I have my rear wheel off I string it when I put it back on. I keep a mental note of the differences on the swing arm markings and then do any subsequent alignments visually but I maintain the offset found during the string alignment.

[nt650hawk]

Motion Pro Tools - Chain Alignment Tool

Nice and cheap $25 or so.

It clamps on the rear sprocket and you place a 6-" rod into a holder above the chain. This is centered on the sprocket. Then you sight down the rod (like a gun) towards the front sprocket till it looks like it lined up with the center of the front sprocket. You are done.




This does not work for a single sided swing arm. Are you

[TTD]

Man Tony that thing is $150 !

Yeah... I wouldn't have bought it.

It came with my TZ250 purchase.

[Bokey]

I made my own verified by the string method.

[DucDave]

Which side of your mouth do you stick your tongue out when eyeballing it?

[FireboltEric_MA]

The cheapest method I have found to work very well is to use some old floresent lights, long tube style. One on each side for perfect alignment...

Buying the tool is much easier and less messy when them tubes break on ya...

[Mad Max]

On the SV, the problem with using the hash marks is that what is indicating which hash mark it's on is the washer. The washer fits on the axle and the washers have some slop in them. It's not the placement of the washers that matter so using the hash marks you have make sure that all the slop is on one side for both washers.